Reportable Segments (Schedule of Assets of Reportable Segments) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Property, Equipment, Land and Leasehold Improvements, net	$ 3,220	$ 3,202
Total Assets	7,626	6,861
IMTT | Operating Segments
Segment Reporting Information [Line Items]
Property, Equipment, Land and Leasehold Improvements, net	2,337	2,323
Total Assets	4,098	4,172
Atlantic Aviation | Operating Segments
Segment Reporting Information [Line Items]
Property, Equipment, Land and Leasehold Improvements, net	568	567
Total Assets	1,967	2,060
MIC Hawaii | Operating Segments
Segment Reporting Information [Line Items]
Property, Equipment, Land and Leasehold Improvements, net	302	301
Total Assets	519	537
Corporate and Other | Operating Segments
Segment Reporting Information [Line Items]
Property, Equipment, Land and Leasehold Improvements, net	13	11
Total Assets	$ 1,042	$ 92